| [section:transformed transformed] |
| |
| [table |
| [[Syntax] [Code]] |
| [[Pipe] [`rng | boost::adaptors::transformed(fun)`]] |
| [[Function] [`boost::adaptors::transform(rng, fun)`]] |
| ] |
| |
| * [*Precondition:] The `value_type` of the range is convertible to the argument type of `fun`. |
| * [*Postcondition:] For all elements `x` in the returned range, `x` is the result of `fun(y)` where `y` is the corresponding element in the original range. |
| * [*Throws:] Whatever the copy-constructor of `fun` might throw. |
| * [*Range Category:] __single_pass_range__ |
| * [*Returned Range Category:] The range category of `rng`. |
| |
| [section:transformed_example transformed example] |
| `` |
| #include <boost/range/adaptor/transformed.hpp> |
| #include <boost/range/algorithm/copy.hpp> |
| #include <boost/assign.hpp> |
| #include <algorithm> |
| #include <iostream> |
| #include <vector> |
| |
| struct double_int |
| { |
| typedef int result_type; |
| int operator()(int x) const { return x * 2; } |
| }; |
| |
| int main(int argc, const char* argv[]) |
| { |
| using namespace boost::adaptors; |
| using namespace boost::assign; |
| |
| std::vector<int> input; |
| input += 1,2,3,4,5,6,7,8,9,10; |
| |
| boost::copy( |
| input | transformed(double_int()), |
| std::ostream_iterator<int>(std::cout, ",")); |
| |
| return 0; |
| } |
| `` |
| [endsect] |
| |
| This would produce the output: |
| `` |
| 2,4,6,8,10,12,14,16,18,20 |
| `` |
| [endsect] |
| |
| |